MASSIVELY PARALLEL DETECTION OF TRACE MOLECULES AND ISOTOPOLOGUES WITH A SUBHARMONIC MID-IR DUAL COMB SYSTEM

\begin{wrapfigure}{l}{0pt} \includegraphics[scale=0.3]{FIG_for_CLEO-2018_on_DCS_v2.eps} \end{wrapfigure} We use a pair of highly-coherent subharmonic GaAs optical parametric oscillators with an instantaneous span 3.1-5.5 $\mu$m to demonstrate fast acquisition of 350,000 mode-resolved spectral data points and perform parallel detection in a mixture of 22 molecular species including N$_{2}$O, NO, CO, OCS, CH$_{4}$, C$_{2}$H$_{6}$, C$_{2}$H$_{4}$, C$_{2}$H$_{2}$, CO$_{2}$, H$_{2}$O, and their isotopologues containing $^{33}$S, $^{34}$S, $^{13}$C, $^{15}$N, $^{18}$O, $^{17}$O, and $^{2}$H (deuterium) isotopes. We demonstrate all the benefits of the mid-IR dual-comb spectroscopy including broadband coverage, fast acquisition of massive spectral data, ppb-level sensitivity, comb-tooth resolved spectra (with finesse 4000) and absolute optical frequency referencing to atomic clock. We sampled molecular spectra with the comb-tooth spacing (115 MHz), however, thanks to the narrow comb teeth (3-kHz absolute and 25-mHz relative linewidth between the two combs), much higher spectral resolution can be obtained in the scanning comb-tooth resolved mode. The Figure shows: (a) schematic of the dual-comb setup, (b) log-scale optical spectrum retrieved from a single coherently-averaged interferogram with an evacuated multipass gas cell, and (c) when the cell was filled with a mixture of gases. The two spectra are vertically offset for clarity

Background-free broadband absorption spectroscopy based on interferometric suppression with a sign-inverted waveform

Background-free methods have potentially superior detection sensitivity because of their ability to take advantage of the full laser power; they are therefore attractive to spectroscopists. We implement background-free Fourier transform spectroscopy based on coherent suppression of the background using an interferometer, whereby the central peak of the interferogram is suppressed without losing molecular absorption signatures. This results in the appearance of peaks rather than dips in the measured spectrum. The technique can be used with a variety of broadband spectroscopies and features advantages such as a reduction in the required detector dynamic range, the capability to perform quantitative measurements, and strongly enhanced sensitivity down to the quantum limit. We validated our method experimentally by performing mid-infrared dual-comb spectroscopy with a mixture of multiple molecular species over a broad wavelength range of 3-5 mu m. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing AgreementPeer reviewe

Coherence properties of a broadband femtosecond mid-IR optical parametric oscillator operating at degeneracy

We study coherence properties of a χ^(2) optical parametric oscillator (OPO), which produces 2/3-octave-wide spectrum centered at the subharmonic (3120 nm) of the femtosecond pump laser. Our method consists of interfering the outputs of two identical, but independent OPOs pumped by the same laser. We demonstrate that the two OPOs show stable spatial and temporal interference and are mutually locked in frequency and in phase. By observing a collective heterodyne beat signal between the two OPOs we show that one can deterministically choose, by cavity length adjustment, between the two frequency states corresponding to the two sets of modes shifted with respect to each other by half of the laser pulse repetition rate. Moreover, we observe that the existence of two opposite phase states, a known common feature of a parametrically driven n = 2 subharmonic oscillator, reveals itself in our experiment as a common phase, 0 or π, being established through the whole set of some 300 thousand longitudinal modes

Fractional-length sync-pumped degenerate optical parametric oscillator for 500-MHz 3-μm mid-infrared frequency comb generation

We demonstrate a mid-IR frequency comb centered at 3120 nm with 650-nm (20-THz) bandwidth at a comb-teeth spacing of 500 MHz. The generated comb is based on a compact ring-type synchronously pumped optical parametric oscillator (SPOPO) operating at degeneracy and pumped by a mode-locked Er-doped 1560 nm fiber laser at a repetition rate of 100 MHz. We achieve high-repetition rate by using a fractional-length cavity with a roundtrip length of 60 cm, which is one-fifth of the length dictated by conventional synchronous pumping

Octave-spanning ultrafast OPO with 2.6-6.1µm instantaneous bandwidth pumped by femtosecond Tm-fiber laser

We report the extension of broadband degenerate OPO operation further into mid-infrared. A femtosecond thulium fiber laser with output centered at 2050 nm synchronously pumps a 500-μm-long crystal of orientation patterned GaAs providing broadband gain centered at 4.1 µm. We observe a pump threshold of 17 mW and output bandwidth extending from 2.6 to 6.1 µm at the −30 dB level. Average output power was 37 mW. Appropriate resonator group dispersion is a key factor for achieving degenerate operation with instantaneously broad bandwidth. The output spectrum is very sensitive to absorption and dispersion introduced by molecular species inside the OPO cavity

All-Optical Quantum Random Bit Generation from Intrinsically Binary Phase of Parametric Oscillators

True random number generators (RNGs) are desirable for applications ranging from cryptogra- phy to computer simulations. Quantum phenomena prove to be attractive for physical RNGs due to their fundamental randomness and immunity to attack [1]- [5]. Optical parametric down conversion is an essential element in most quantum optical experiments including optical squeezing [9], and generation of entangled photons [10]. In an optical parametric oscillator (OPO), photons generated through spontaneous down conversion of the pump initiate the oscillation in the absence of other inputs [11, 12]. This quantum process is the dominant effect during the oscillation build-up, leading to selection of one of the two possible phase states above threshold in a degenerate OPO [13]. Building on this, we demonstrate a novel all-optical quantum RNG in which the photodetection is not a part of the random process, and no post processing is required for the generated bit sequence. We implement a synchronously pumped twin degenerate OPO, which comprises two identical independent OPOs in a single cavity, and measure the relative phase states of the OPO outputs above threshold as a bit value. We show that the outcome is statistically random with 99% confidence. With the use of micro- and nanoscale OPO resonators, this technique offers a promise for simple, robust, and high-speed on-chip all-optical quantum random number generators

Coherence properties of a broadband femtosecond mid-IR optical parametric oscillator operating at degeneracy

We study coherence properties of a χ^(2) optical parametric oscillator (OPO), which produces 2/3-octave-wide spectrum centered at the subharmonic (3120 nm) of the femtosecond pump laser. Our method consists of interfering the outputs of two identical, but independent OPOs pumped by the same laser. We demonstrate that the two OPOs show stable spatial and temporal interference and are mutually locked in frequency and in phase. By observing a collective heterodyne beat signal between the two OPOs we show that one can deterministically choose, by cavity length adjustment, between the two frequency states corresponding to the two sets of modes shifted with respect to each other by half of the laser pulse repetition rate. Moreover, we observe that the existence of two opposite phase states, a known common feature of a parametrically driven n = 2 subharmonic oscillator, reveals itself in our experiment as a common phase, 0 or π, being established through the whole set of some 300 thousand longitudinal modes

PEMBERDAYAAN PEREMPUAN BERBASIS KREATIFITAS DI DUSUN MOJOREJO DESA JUNREJO KOTA BATU

Keadaan perekonomian saat ini sangat memprihatinkan khususnya di Indonesia yang terdapat berbagai permasalahan yang menyangkut mengenai kehidupan bermasyarakat, antara lain masalah kemiskinan, masalah pengangguran, masalah lingkungan hidup, dan lain-lain. Permasalahan tersebut timbul akibat semakin meningkatnya keadaan ekonomi yang tidak disesuaikan dengan kondisi masyarakat. Khususnya masyarakat menengah kebawah. Kemiskinan menjadi masalah yang penting saat ini di Indonesia, sehingga menjadi suatu fokus perhatian bagi pemerintah Indonesia. Masalah kemiskinan ini sangatlah kompleks karena berkaitan dengan aspek sosial, ekonomi, budaya, dan aspek lainnya. Kemiskinan terus menjadi masalah fenomenal di belahan dunia, khususnya Indonesia yang merupakan negara berkembang. Kemiskinan telah membuat jutaan anak tidak bisa mengenyam pendidikan, kesulitan membiayai kesehatan, kurangnya tabungan dan investasi, dan masalah lain yang menjurus ke arah tindakan kekerasan dan kejahatan. Kemisikinan menjadi salah satu fenomena masalah yang kerap kita temui di majalah, surat kabar, ataupun berita online lainnya. Dinas sosial Kota Batu setidaknya mencatat ada 2.339 keluarga miskin sedangkan badan pusat statistik menerangkan jumlah keluarga miskin mencapai 2.600 keluarga miskin. Ini cukup membuktikan untuk menjelaskan bahwa masih banyak keluarga Kota Batu yang masih harus berjuang hanya untuk sekedar membiayai anaknya masuk sekolah. Pemberdayaan menjadi salah satu alternatif untuk menyelesaikan masalah terkait dengan pengentasan kemiskinan. Dalam penelitian ini terkait dengan program pemberdayaan yang dilakukan oleh kelompok mahasiswa Universitas Muhammadiyah Malang dan didanai oleh DIKTI dari Program Kreatifitas Mahasiswa (PKM) yang mana saya termasuk dalam kelompok tersebut. Pengabdian masyarakat dalam bentuk pemberdayaan masyarakat ini mempunyai subyek pemberdayaan perempuan dusun Wonorejo Desa Junrejo Kota Batu. Proses pemberdayaan dilakukan selama tiga bulan di dusun setempat

Octave-spanning ultrafast OPO with 2.6-6.1µm instantaneous bandwidth pumped by femtosecond Tm-fiber laser

We report the extension of broadband degenerate OPO operation further into mid-infrared. A femtosecond thulium fiber laser with output centered at 2050 nm synchronously pumps a 500-μm-long crystal of orientation patterned GaAs providing broadband gain centered at 4.1 µm. We observe a pump threshold of 17 mW and output bandwidth extending from 2.6 to 6.1 µm at the −30 dB level. Average output power was 37 mW. Appropriate resonator group dispersion is a key factor for achieving degenerate operation with instantaneously broad bandwidth. The output spectrum is very sensitive to absorption and dispersion introduced by molecular species inside the OPO cavity

Sub-50 fs pulses around 2070 nm from a synchronously-pumped, degenerate OPO,” Opt

Abstract: We report generation of 48 fs pulses at a center wavelength of 2070 nm using a degenerate optical parametric oscillator (OPO) synchronously-pumped with a commercially available 36-MHz, femtosecond, mode-locked, Yb-doped fiber laser. The spectral bandwidth of the output is ~137 nm, corresponding to a theoretical, transform-limited pulse width of 33 fs. The threshold of the OPO is less than 10 mW of average pump power. By tuning the cavity length, the output spectrum covers a spectral width of more than 400 nm, limited only by the bandwidth of the cavity mirrors. Griebner, "175 fs Tm:Lu 2 O 3 laser at 2.07 µm mode-locked using single-walled carbon nanotubes," Opt. Express 20(5), 5313-5318 (201